中华网络安全联盟    作者：奇趣    来源：奇趣技术网    时间：2008-5-28 14:35:46

算一算，自从上次发表一篇asp.net中用VML画数据统计图的文章后差不多有一两个月没有来博客了，今天中秋，没事做发现自己已经很久没有来博客园了.正好前几天有小做一个视频转换的Demo,现在出现很的网上在线视频其文件格式都是.FLV格式，那些视频网站大概也有一个视频转换软件，所我在也试着去做了一个demo拿出来和大家共享一下，由于自己的技术有限，做的不怎么样，愿有高人看完给
在下指点一二.呵....　费话不多说了，下面来分解一下这个Demo.

首先，我们部署一下文件夹.在工程的目录下新建几个文件夹如下图： 
中将视频文件转换成.flv格式UpFiles文件夹是要保存你上传的文件，PlayFiles文件夹是用于你转换后保存的文件（用于网上播放）

ImgFile文件夹是保存截取视频文件的图片，然后那两个mencoder和ffmpeg文件夹是视频转换工具.此视频转换也
可叫做mencoder+ffmpeg视频转换.
首先，在配置文件中给这些文件夹进行路径的配置.如下

<appSettings>
<!--工具文件夹-->
<add key="ffmpeg" value="ffmpeg/ffmpeg.exe"/>
<add key="mencoder" value="mencoder/mencoder.exe"/>
<add key="mplayer" value="mencoder/mplayer.exe"/>
<!--上传文件的路径-->
<add key="upfile" value="UpFiles"/>
<!--上专文件图片路径-->
<add key="imgfile" value="ImgFile"/>
<!--上传文件图片大小-->
<add key="CatchFlvImgSize" value="240x180"/>
<add key="widthSize" value="400"/>
<add key="heightSize" value="350"/>
<!--转换后文件路径-->
<add key="playfile" value="PlayFiles"/>
</appSettings>在上传.ASPX页面中

标题：<asp:TextBox ID="txtTitle" runat="server" Width="358px"></asp:TextBox>
<asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ControlToValidate="txtTitle"
ErrorMessage="标题不为空"></asp:RequiredFieldValidator>
<br />
<asp:FileUpload ID="FileUpload1" runat="server" Width="339px" />
<asp:Button ID="btnUpload" runat="server" OnClick="btnUpload_Click" Text="上传视频" Width="70px" />
文件类型<span style="color:Red;">(.asf　.flv　.avi　.mpg　.3gp　.mov　.wmv　.rm　.rmvb)</span>
<asp:RegularExpressionValidator ID="imagePathValidator" runat="server" ErrorMessage="文件类型不正确"
ValidationGroup="vgValidation" Display="Dynamic" ValidationExpression="^[a-zA-Z]:(\\.+)(.asf　.flv　.avi　.mpg　.3gp　.mov　.wmv　.rm　.rmvb)$"
ControlToValidate="FileUpload1">
</asp:RegularExpressionValidator>
<asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="FileUpload1"
ErrorMessage="文件不为空"></asp:RequiredFieldValidator></div>
<div style=" height:0px; border-top:solid 1px red; font-size:0px;"></div>

public partial class _Default : System.Web.UI.Page
{
// 扩展名定义
string[] strArrFfmpeg = new string[] {"asf","avi","mpg","3gp","mov" };
string[] strArrMencoder = new string[] {"wmv","rm","rmvb" };
protected void Page_Load(object sender, EventArgs e)
{

}
//
protected void btnUpload_Click(object sender, EventArgs e)
{

string upFileName = "";
if (this.FileUpload1.HasFile)
{
string fileName = PublicMethod.GetFileName(this.FileUpload1.FileName);// GetFileName();
if ((string)Session["file"] == fileName)
{
return;
}
upFileName = Server.MapPath(PublicMethod.upFile + fileName);
this.FileUpload1.SaveAs(upFileName);
string saveName = DateTime.Now.ToString("yyyyMMddHHmmssffff") ;
string playFile = Server.MapPath(PublicMethod.playFile + saveName);
string imgFile = Server.MapPath(PublicMethod.imgFile + saveName);
//System.IO.File.Copy(Server.MapPath(PublicMethod.playFile + "00000002.jpg"), Server.MapPath(PublicMethod.imgFile+"aa.jpg"));
PublicMethod pm = new PublicMethod();
string m_strExtension = PublicMethod.GetExtension(this.FileUpload1.PostedFile.FileName).ToLower();
if (m_strExtension == "flv")
{//直接拷贝到播放文件夹下
System.IO.File.Copy(upFileName, playFile+".flv");
pm.CatchImg(upFileName, imgFile);
}
string Extension = CheckExtension(m_strExtension);
if (Extension == "ffmpeg")
{
　pm.ChangeFilePhy(upFileName, playFile, imgFile);
}
else if (Extension == "mencoder")
{
pm.MChangeFilePhy(upFileName, playFile, imgFile);
}
InsertData(this.txtTitle.Text, fileName,saveName);
Session["file"] = fileName;
}

}

//
private string CheckExtension(string extension)
{
string m_strReturn = "";
foreach (string var in this.strArrFfmpeg)
{
if (var == extension)
{
m_strReturn = "ffmpeg"; break;
}
}
if (m_strReturn == "")
{
foreach (string var in strArrMencoder)
{
if (var == extension)
{
m_strReturn = "mencoder"; break;
}
}
}
return m_strReturn;
}
#region 插入数据到数据库中
private void InsertData(string MediaName,string fileName,string saveName)
{
//string name=fileName.Substring(0, fileName.LastIndexOf('.'));
string imgName = saveName + ".jpg";//图片文件名;
string playName = saveName + ".flv";
string sqlstr = "insert into Media(FMediaName,FMediaUpPath,FMediaPlayPath,FMediaImgPath) values(@MName,@MUppath,@MPlaypath,@MImgpath)";
//string constr = ConfigurationManager.ConnectionStrings["sqlcon"].ToString();
SqlDataSource1.InsertCommand = sqlstr;
SqlDataSource1.InsertCommandType = SqlDataSourceCommandType.Text;// CommandType.Text;
SqlDataSource1.InsertParameters.Add("MName",MediaName);
SqlDataSource1.InsertParameters.Add("MUppath",PublicMethod.upFile+fileName);
SqlDataSource1.InsertParameters.Add("MPlaypath",PublicMethod.playFile+playName);
SqlDataSource1.InsertParameters.Add("MImgpath",PublicMethod.imgFile+imgName);
SqlDataSource1.Insert();
}
#endregion

}

它的主要原理是另起一个进程在转换的时候你会发现你的进程里多了一个.
using System;
using System.Configuration;

/// <summary>
/// Summary description for PublicMethod
/// </summary>
public class PublicMethod:System.Web.UI.Page
{
public PublicMethod()
{

string flv_file = System.IO.Path.ChangeExtension(playFile, ".flv");

System.Diagnostics.ProcessStartInfo FilestartInfo = new System.Diagnostics.ProcessStartInfo(ffmpeg);

FilestartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;

FilestartInfo.Arguments = " -i " + fileName + " -ab 56 -ar 22050 -b 500 -r 15 -s " + widthOfFile + "x" + heightOfFile + " " + flv_file;
//ImgstartInfo.Arguments = " -i " + fileName + " -y -f image2 -t 0.05 -s " + FlvImgSize + " " + flv_img;

try
{
//转换
System.Diagnostics.Process.Start(FilestartInfo);
//截图
CatchImg(fileName, imgFile);
//System.Diagnostics.Process.Start(ImgstartInfo);
}
catch
{
return "";
}
//
return "";
}
//
public string CatchImg(string fileName,string imgFile)
{
//
string ffmpeg = Server.MapPath(PublicMethod.ffmpegtool);
//
string flv_img =imgFile+".jpg";
//
string FlvImgSize = PublicMethod.sizeOfImg;
//
System.Diagnostics.ProcessStartInfo ImgstartInfo = new System.Diagnostics.ProcessStartInfo(ffmpeg);
ImgstartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
//
ImgstartInfo.Arguments = " -i " + fileName + " -y -f image2 -ss 2 -vframes 1 -s " + FlvImgSize + " " + flv_img;
try
{
System.Diagnostics.Process.Start(ImgstartInfo);
}
catch
{
return "";
}
//
if (System.IO.File.Exists(flv_img))
{
return flv_img;
}

return "";
}
#endregion
//
#region //运行FFMpeg的视频解码，(这里是(虚拟)相对路径)
/// <summary>
/// 转换文件并保存在指定文件夹下面(这里是相对路径)
/// </summary>
/// <param name="fileName">上传视频文件的路径（原文件）</param>
/// <param name="playFile">转换后的文件的路径（网络播放文件）</param>
/// <param name="imgFile">从视频文件中抓取的图片路径</param>
/// <returns>成功:返回图片虚拟地址; 失败:返回空字符串</returns>
public string ChangeFileVir(string fileName, string playFile, string imgFile)
{
//取得ffmpeg.exe的路径,路径配置在Web.Config中,如:<add key="ffmpeg" value="E:\51aspx\ffmpeg.exe" />
string ffmpeg = Server.MapPath(PublicMethod.ffmpegtool);
if ((!System.IO.File.Exists(ffmpeg)) 　　 (!System.IO.File.Exists(fileName)))
{
return "";
}

System.Diagnostics.ProcessStartInfo FilestartInfo = new System.Diagnostics.ProcessStartInfo(ffmpeg);
System.Diagnostics.ProcessStartInfo ImgstartInfo = new System.Diagnostics.ProcessStartInfo(ffmpeg);

FilestartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
ImgstartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
//此处组合成ffmpeg.exe文件需要的参数即可,此处命令在ffmpeg 0.4.9调试通过
//ffmpeg -i F:\01.wmv -ab 56 -ar 22050 -b 500 -r 15 -s 320x240 f:\test.flv
FilestartInfo.Arguments = " -i " + fileName + " -ab 56 -ar 22050 -b 500 -r 15 -s " + widthOfFile + "x" + heightOfFile + " " + flv_file;
ImgstartInfo.Arguments = " -i " + fileName + " -y -f image2 -t 0.001 -s " + FlvImgSize + " " + flv_img;

try
{
System.Diagnostics.Process.Start(FilestartInfo);
System.Diagnostics.Process.Start(ImgstartInfo);
}
catch
{
return "";
}

/**/
///注意:图片截取成功后,数据由内存缓存写到磁盘需要时间较长,大概在3,4秒甚至更长;
///这儿需要延时后再检测,我服务器延时8秒,即如果超过8秒图片仍不存在,认为截图失败;
///此处略去延时代码.如有那位知道如何捕捉ffmpeg.exe截图失败消息,请告知,先谢过!
if (System.IO.File.Exists(flv_img))
{
return flv_img;
}

return "";
}
#endregion

#region //运行mencoder的视频解码器转换(这里是(绝对路径))
public string MChangeFilePhy(string vFileName, string playFile, string imgFile)
{
string tool = Server.MapPath(PublicMethod.mencodertool);
//string mplaytool = Server.MapPath(PublicMethod.ffmpegtool);

if ((!System.IO.File.Exists(tool)) 　　 (!System.IO.File.Exists(vFileName)))
{
return "";
}

string flv_file = System.IO.Path.ChangeExtension(playFile, ".flv");

//截图的尺寸大小,配置在Web.Config中,如:<add key="CatchFlvImgSize" value="240x180" />
string FlvImgSize = PublicMethod.sizeOfImg;

System.Diagnostics.ProcessStartInfo FilestartInfo = new System.Diagnostics.ProcessStartInfo(tool);

FilestartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
FilestartInfo.Arguments = " " + vFileName + " -o " + flv_file + " -of lavf -lavfopts
i_certify_that_my_video_stream_does_not_use_b_frames -oac mp3lame -lameopts abr:br=56 -ovc lavc
-lavcopts vcodec=flv:vbitrate=200:mbd=2:mv0:trell:v4mv:cbp:last_pred=1:dia=-1:cmp=0:vb_strategy=1
-vf scale=" + widthOfFile + ":" +heightOfFile + " -ofps 12 -srate 22050";
try
{
System.Diagnostics.Process.Start(FilestartInfo);
CatchImg(flv_file, imgFile);
}
catch
{
return "";
}
//
return "";
}
#endregion
}

全文的主要内容就在这里了

还有其视频转换工具，由于比较大有十多MB博客上传不了.所以还需大家另外去下载